What do you call a baby fish?

Answer: fry, fingerling

A baby fish is called a fry, fingerling. Fish are aquatic vertebrate animals that are typically ectothermic (previously cold-blooded), covered with scales, and equipped with two sets of paired fins and several unpaired fins. Fish are abundant in the sea and in fresh water, with species being known from mountain streams (e.g., char and gudgeon) as well as in the deepest depths of the ocean (e.g., gulpers and anglerfish).